The present teachings relate to a device for cooling optical components based on optical fibers for transmitting high optical power.
Fiber-coupled laser-diodes are used directly or as sources to optically-pump solid-state lasers, including fiber-lasers and fiber-amplifiers. In order to optimize the optical power coupled into the fiber core, a certain amount of optical power is also coupled into the fiber cladding. The power in the cladding is undesirable since it may cause damage to the solid-state laser. A mode stripper is used to remove the optical power in the fiber cladding. The mode stripper scatters the light in a localized region. The scattered light is generally absorbed for safety reasons and to prevent optical damage to the laser system. The power handling capability of the mode stripper is determined by the ability to remove the heat from the absorbed light. The mode stripper generally fails if the local temperature exceeds ˜100° C. since there are polymers in close proximity.
In the traditional techniques, the heat is removed by an air cooled or water cooled heatsink. The thermal resistance of the heatsink, i.e. the ability of the heatsink to remove heat vary depending on the heatsink design. For military applications, these heatsinks need to be small in size and weight. Small (˜2-4 cm in dimension) commercial air-cooled heat-sinks remove ˜30 W of heat and small commercial water-cooled heat-sinks remove ˜85 W of heat. To remove larger amounts of heat, the size and weight of heat-sinks are generally unacceptable for military applications.